As its name suggests, human growth hormone (HGH) — also known as growth hormone (GH) — is a natural compound that stimulates tissue and bone growth in humans. Along with growth, this powerful hormone also regulates metabolic, cognitive, and adrenal function, among other things.

Human growth hormone is best known for stimulating growth in adolescence, and as a performance-enhancing supplement in adults. Some even claim that HGH treatment has anti-aging effects.

For most people, however, growth hormone injections carry risky consequences. Fortunately, there are natural ways to boost HGH and get the benefits without the side effects.

What is Human Growth Hormone?

Human growth hormone goes by many names. HGH, GH, somatotropin — they all refer to the same chemical messenger produced in the pituitary gland — a gland about the size of a pea behind the bridge of your nose[*].

Growth hormone was originally discovered as a growth promoter in infants and adolescents, but researchers now know its influence on protein production, fat utilization, blood sugar and insulin levels, and more.

HGH levels start to decline around age 30, decreasing by a factor of two or three during the fourth decade of life, and continuing to decline with age[*].

Your pituitary gland releases HGH in small bursts, usually after exercise or during deep sleep. This makes it a little more difficult to measure HGH in the blood, because levels fluctuate throughout the day.

And like all hormones, growth hormone doesn’t work alone. HGH secretion is regulated by several other compounds.

Let’s dive into the hormones and other cofactors that stimulate GH naturally.

What Stimulates Growth Hormone Secretion?

Of the many chemicals that regulate HGH levels, here are the main players[*]:

#1 Ghrelin

Ghrelin is your main hunger hormone, produced mainly in the stomach, with small amounts produced in your small intestine, pancreas, and brain[*]. Ghrelin rises in response to low blood sugar, stimulating your appetite so you know when your body needs more food for energy.

JAKs bind to transcription factors called STATs and carry them into the cell’s nucleus

Your nuclear genes tell the cell to start producing IGF-1

And now you have IGF-1. Combined, HGH and IGF-1 influence many functions in your body.

Primary Functions of Growth Hormone

#1 HGH Stimulates Growth

There are two ways that HGH promotes growth.

The first is the direct pathway.

HGH binds to chondrocytes and osteoblasts — cells that promote, bone and cartilage growth[*]. This action, as you might imagine, is crucial for growing children.

The biochemistry behind cellular growth is complex, but simply put: HGH tells proteins to swim to the cell’s nucleus, these proteins nudge your genes, and your genes tell your body to grow more bone and cartilage.

The second HGH growth-promoting pathway is more indirect.

Remember IGF-1? Some scientists argue that HGH is merely a precursor to this more powerful growth factor[*]. IGF-1, they say, is the key hormone for growth, repair, healing, cellular replication, and so much more.

You release more HGH when blood sugar is low. Growth hormone then binds to your liver, causing an uptick in gluconeogenesis — a process by which your liver creates glucose from protein.

Because of this, too much HGH can cause high blood sugar, though this is way more likely if you’re using synthetic HGH, not if you’re boosting HGH naturally.

Benefits of Human Growth Hormone

Benefits of more HGH include stronger bones and cartilage, more muscle mass, and better performance and energy levels.

But that doesn’t mean you should start supplemental growth hormone. Though some people benefit from synthetic HGH, most researchers advise caution and up to 30% of users report uncomfortable — and sometimes dangerous — side effects[*].

Instead, these are practical reasons to boost HGH naturally. And it’s easier than it sounds.

Benefit #1: Muscle Growth And Retention

HGH is known for boosting muscle growth and preventing age-related muscle decline.

This works in a couple of ways:

As you age, you’re more likely to lose muscle due to an increase in a muscle-shrinking hormone called myostatin. Growth hormone inhibits myostatin (mostly through IGF-1 and another pro-growth pathway called mTor)[*].

Also, although centenarians (people over 100) have lower IGF-1 than the general population, the centenarians with the lowest levels also have increased dementia risk[*].

But excess IGF-1 is also no good. It’s linked to increased mortality, probably from higher cancer risk[*]. IGF-1 is a potent growth signal — not just in normal cells — but in cancer cells too[*].

Bottom line? To age better, you need some HGH, but be wary of excess unless you’re obviously deficient.

Benefit #5: Brain Function

Your central nervous system can synthesize HGH and IGF-1, and both are critical for early brain development[*].

Growth hormone also may trigger new brain cell growth (neurogenesis) after brain injury or age-related cognitive decline[*]. For example: after administering GH to older mice, researchers noticed new neurons in both the cortical and hippocampal regions of their brains.

Such promising results on humans are yet to come, but it’s well-documented that older adults with GH deficiency can be helped — both emotionally and cognitively — by supplemental growth hormone[*].

Benefit #6: Liver Repair

The human liver contains many growth hormone receptors. Unsurprisingly, those with growth hormone deficiency tend to suffer from liver dysfunction[*].

When the liver gets injured, HGH comes to the rescue. It repairs the damage.

The liver, by the way, has an incredible ability to regenerate. You can cut someone’s liver in half, and — provided that person is healthy — the liver will fully regrow[*]. With the help of GH, of course.

Benefit #7: Cardiovascular Health

In the growing fetus, growth hormone functions as a myocardial (heart muscle) growth signal. HGH also increases the force of contraction, increasing fetal blood flow, which means more nutrients and oxygen delivery to cells[*].

In adults too, growth hormone has many cardiac-related roles. For one, HGH helps coat the heart with necessary collagen.

Many people — athletes, mainly — also inject growth hormone for off-label, muscle-building purposes. But as you learned, there’s little wisdom or evidence behind this practice.

Must synthetic HGH be injected? Yes.

Despite the claims of many marketers, injections are the only proven (and FDA approved) way to take synthetic growth hormone. There’s simply no evidence for the efficacy of HGH pills, sprays, or powders.

#1 Sleep Well

Since growth hormone declines with age, adequate deep sleep is a non-negotiable for older adults, with GH beginning to decrease two- to threefold between age 30-40[*]. No matter your age, however, GH production suffers when you don’t sleep enough.

Bottom line: Fasting or intermittent fasting (IF) can increase HGH. For more about IF, read this.

#7 Go Keto

The ketogenic diet is a high-fat, low-carb diet that puts you in a unique metabolic state called ketosis. In ketosis: you burn less glucose, burn more fat, and produce ketones. The result of these changes is stable energy, clear cognition, and fewer cravings.

Optimize Your HGH

After age 30, growth hormone starts to decline.

Luckily, you can mitigate the effects of this decline — weak muscles, brittle bones, slower cognition, etc. — without hormone injections. Considering the side effects of synthetic growth hormone, this is good news.